1. Field Of The Invention
This invention relates to a sling for use in hoisting boats or other heavy objects. More particularly, this invention relates to a sling of the foregoing character which is encapsulated with suitable protective elements to prevent the sling from being damaged by ultraviolet light and/or by dirt and gravel and other abrasive substances that the sling can contact during its normal use, and to prevent or substantially prevent the sling from damaging the surfaces of the objects it is used to hoist.
2. Description Of The Prior Art
My prior U.S. Pat. No. 5,037,237, the disclosure of which is hereby incorporated by reference, describes the use of slings in hoisting a boat, and discusses the problems of contact damage that can be caused to a boat during hoisting by dirt or gravel or other debris that can be picked up by a sling, especially a sling of a coarse texture. The aforesaid U.S. Pat. No. 5,037,237 solves such problems by teaching the use of separate protectors releasably affixed to the lifelines or other elements of the boat and positioned between the hull of the boat and each of the slings used to hoist the boat to thereby prevent such contact damage. However, many marinas are reluctant to use protectors of the type taught in the aforesaid U.S. Pat. No. 5,037,237, because the affixing of the protectors to the boat prior to the hoisting operation, and the removal of the protectors after the hoisting operation, slows down the hoisting operation and therefore at least somewhat increases the initial expense to the marina in conducting its hoisting operations.
While the use of protectors according to the aforesaid U.S. Pat. No. 5,037,237 is quite effective in preventing contact damage to a boat or other hoisted object from debris carried by a sling, it does not protect the sling from abrasion or other contact damage caused by the initial and subsequent relative motion and other contact between the sling and such debris, which can materially shorten the useful life of a sling relative to that of a comparable sling which is not suitably protected from such contact. Further, many slings are woven from polyester or polyamide (Nylon) or other ultraviolet light sensitive materials, and ultraviolet light degradation of such slings can also materially shorten the life of such slings, especially those used in Southern states of the United States and in other locations having similar climatic conditions. U.S. Pat. No. 3,622,025 (Peterson) teaches the use of pads to protect a boat sling from damage by contact with fittings on the hulls of hoisted boats. However, the protective pads of this reference are too short and too narrow to protect the eyes and the edges of a sling from the kinds of damage that can occur when a sling is dragged across rough terrain and do not protect enough of the length of the sling to effectively retard ultraviolet light degradation of slings made from light sensitive materials.